The Planck Mission Planck the fourth space mission

The Planck Mission Planck, the fourth space mission to measure the anisotropy of the cosmic microwave background (CMB), will launch with the Herschel Space Observatory in 2008 on an Ariane 5 rocket. With an unprecedented combination of sensitivity, angular resolution, and frequency coverage, Planck is designed to extract essentially all information available in the primary temperature anisotropies, and to measure the polarization to high accuracy. Planck will image CMB anisotropies with high SNR with two state-of-the-art cryogenic instruments, the Low Frequency Instrument (LFI, 30 -70 GHz) and the High Frequency Instrument (HFI, 100 -857 GHz). By giving a clear view of the Universe at z 1000, these measurements will provide • unprecedented tests of inflation and the physics of the ultra-early Universe • determination of cosmological parameters to extraordinarily high precision • new understanding of dark energy • the ionization history of the Universe • an unbiased catalog of thousands of galaxy clusters • the large-scale distribution of matter in the Universe, through gravitational lensing Planck will orbit at the Earth-Sun L 2 point, spinning at 1 rpm with its spin axis pointed near the Sun. The entire sky is scanned every six months.

Frequency Coverage Planck Extends Our Knowledge of the CMB Planck's wide frequency coverage will permit separation of the CMB and foreground sources of radiation with different spectra. Dust, free-free, synchrotron, and ΔCMB levels are as measured by WMAP on ~1° angular scales. The left panel shows a realization of the CMB power spectrum of the concordance ΛCDM model (red line) after 4 years of WMAP observations. The right panel shows the same realization observed with the sensitivity and angular resolution of Planck. Forecasts for the 1 errors on the E-mode polarization power spectrum in a ΛCDM model (with r = 0. 1 and t�= 0. 17) from WMAP (4 years of observation) and BOOMERan. G 2 K (left) and Planck (right). For WMAP and B 2 K, flat band powers are estimated with D = 150 (with finer resolution on large scales for WMAP in the inset). For Planck, flat band powers are estimated with D = 20 in the main plot, but with D = 2 in the inset on large scales. Optical System The telescope field-of-view is offset from the spin axis of the satellite by an angle of 85°. The footprint of the field-ofview on the sky is seen in the left panel; it covers about 8° on the sky at its widest. Each spot corresponds to the 20 d. B contour of the radiation pattern seen by each detector. The black crosses indicate the orientation of pairs of linearly polarized detectors within each horn. The direction in which the field-of-view sweeps the sky is the horizontal in this diagram. Summary of Planck Instrument Characteristics